1. Field of the Invention
The present invention relates to a compact electronic apparatus including a plurality of circuit boards mounted with circuit components and various functional components such as a cathode ray tube (CRT), a liquid crystal display (LCD) unit, an audio/video drive and a hard disc drive contained in a metal or synthetic resin cabinet and adapted to be driven by a commercial power supply.
2. Description of the Related Art
Prior art compact electronic apparatuses for daily personal use include television sets, video recorders, personal computers, radio receiving sets, video cameras, stereophonic audio systems, portable cassette players and portable compact disc (CD) players. For example, a personal computer includes a circuit board mounted with a control unit formed by a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), etc., and various functional components such as a floppy disc drive, a hard disc drive, a CD-ROM drive, a power supply unit, an amplifier, and extension cage for accommodating an extension board, a CRT monitor, an LCD unit and a loudspeaker. In most conventional personal computers, these functional components are mounted on a single base frame or a single cabinet. Screws, bolts and nuts, snap fit connectors, adhesives and other various mechanical connectors that are different in profile, size and material are used to physically link the components. Also, various electric connectors are used for electrically connecting related components.
On the other hand, a stereophonic audio system typically includes functional components such as a power supply unit, an amplifier, a radio tuner, a television tuner, a CD player, a mini disc (MD) player, a tape player and loudspeakers. In the case of a so-called component type stereophonic audio system, these functional components are mounted on respective base frames or cabinets to form units. The physical linkage of the functional components may be realized by simply laying the units one by one or by placing them in position in a system rack and securing them by mechanical connecting means such as screws. Common connectors are used to electrically connect the units.
Car audio systems also employ a mounting technique similar to the one used for component type stereophonic audio systems.
In the case of a unitary type stereophonic audio system, functional components are mounted on a single base frame or a cabinet like a unitary type personal computer. Like a unitary type personal computer, screws, bolts and nuts, snap fit connectors that are different in profile, size and material are used to physically link the components. Also, various electric connectors are used for electrically connecting the related components.
Now, of various conventional compact electronic apparatuses, personal computers may be subjected to various operations of installing one or more than one additional circuit components on the circuit board or the extension cage and/or one or more than one additional drives for driving a storage medium and replacing some of the circuit components with revised ones in order to modify the operating environment of the computer to adapt it to the installed application software or the various devices connected to the computer depending, of course, on the application software or the devices in question. In order to cope with the above-mentioned situations, various arrangements have been developled.
In a first prior art personal computer, the screws connecting the cabinet to the base frame may be so designed that they can be unscrewed by means of a coin without requiring the use of a specific tool. A unit may be provided for the extension cage so that an additional circuit board may be installed in the computer main body by simply removing the lid of an insertion slot without dismantling the cabinet.
A second prior art personal computer can optionally contain a pack unit as a module to be connected to the circuit of the computer (see JP-A-3-30007).
In a third prior art personal computer, a plurality of circuit boards are arranged on a one on the other basis and a space is provided for receiving additional circuit components in the future so that additional circuit components may be installed and any of the existing circuit components may be replaced without removing the circuit board unit from the cabinet and disassambling the circuit board unit (see JP-A-6-110579).
In a fourth prior art personal computer, functional components are provided so that many units may be connected by means of common connectors without using specific tools to improve the service life of the equipment and make it to be easily disassambled and disposed when it is discarded as waste (see JP-A-7-21428).
Thus, the functional components mounted on today's compact electronic apparatuses such as personal computers, stereophonic audio system, television sets and video recorders are physically and electrically connected in a manner specific to each type of product. However, person computers, stereophonic audio systems, television sets, video recorders, video cameras and car audio systems have many functional components that can be commonly used in those apparatuses. For example, a CD player used in a stereophonic audio system may also be used in a car audio system, a car navigation system, a portable CD player or a personal computer. An LCD monitor may be used in a television set, a video camera, a personal computer, a car television set or a car navigation system. A power supply unit or a loudspeaker may find even broader applications including television sets, video recorders, personal computers, radio receiving sets, stereophonic audio systems, car audio systems, portable cassette players and portable CD players.
However, while many of these electric components in various compact electric apparatuses may not be used simultaneously by a single user, none of them is adapted to be removed from an apparatus, put into another apparatus and electrically connected to the remaining components of the latter apparatus. Therefore, unless identical functional components are minimized in an attempt to protect the environment of this planet, the amount of waste originating from them will be enormous as a whole and put a heavy load on the environment. Note that a wireless remote controller is realized by separating the functions common to different home appliances and those not common to them and combining a plurality of units that can be connected with each other (see JP-U-62-152557). However, this controller is effective only for remote controllers and cannot dissolve the load on the environment that is attributable to home appliances.
In the case of the above-described prior art personal computers or prior art unitary type stereophonic audio systems where all the circuit boards, the circuit components and drives are arranged on a single base frame, physically and electrically connected and housed in a single cabinet, the cabinet has to be removed and many of the complicatedly connected components have to be separated from each other at the cost of tremendous labor when replacing a malfunctioning circuit component, a circuit board or a drive has to be replaced or when the entire apparatus is discarded for waste disposal. Sometimes, circuit boards and components that operate well may also be replaced and disposed of which increases the amount of waste and shortens the service life of the personal computers or stereophonic audio systems.